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Advice for difficult corner pin?

PostPosted: Sun Sep 26, 2021 9:17 pm
by TCP786
I'm having trouble with a compositing task and I would love it if anyone could recommend any tips or tricks I might not have thought of so far. I'm compositing an image onto a wall as graffiti, and there are a few things about this particular case that are giving me a bit more trouble than usual.

First of all, there are no markers in the footage, and we have no information about the real world dimensions of the wall I'm compositing onto. Second, I have to do the same composite into at least 6 different shots that are all different angles, and some never have the entire wall in frame. Third, the only points/lines that I can use to eyeball the corners of the corner pin are not where the corners of the comped image will end up, and consequently the aspect ratio of the corner pin region is not the same as the image I'm putting there. And finally, since the composite image is hand drawn text, it has no genuinely vertical or horizontal lines that I can use to try to visually line it up with the real world parallel lines.

Here is an example of a couple shots that I've done the tracking for, as well as some more difficult ones I haven't worked on yet. This example text might be low enough that it might not be visible in the two closer shots, but the text that will actually go in these places will definitely be visible in the shots I haven't worked on yet.

Any advice on how to get all these comps consistent? I'm thinking I might have to make a new image that's the exact same size as the image I'm comping, but full of squares. Then I can adjust that until they look like squares again, then switch out that media for the lettering.

For what it's worth, I don't expect this to be easy, but I also don't expect it to be impossible. Any help is greatly appreciated. Thanks.

Re: Advice for difficult corner pin?

PostPosted: Sun Sep 26, 2021 11:10 pm
by Sander de Regt
Your ambition is admirable, but please remember the reality of filmmaking as you approach this.
1) noone will be looking for the graffiti specifically - except you and the people who asked you to put it there.

2) if this is a regular movie shoot, then the camera, the lighting, the actors would have moved and been placed differently for every seperate take. Sets will be moved around to accomodate the camera etc. So it only has to *look* right.

but 3) if you want to give it a go anyway - you only need to 3d 'track' one shot and then use the info derived from that to do the other shots as well.

Are these static or moving camera shots?

If they're static, you can use a program called fspy to reconstruct the camera, then you can build the wall in a 3D package or you can use an image plane in 3D inside of Fusion to line up to the whole wall. If you do that you have the aspect ratio of the whole wall and you can adjust the corner pin to account for that.

Does this make sense to you?

Re: Advice for difficult corner pin?

PostPosted: Sun Sep 26, 2021 11:30 pm
by TCP786
Yes, that does make sense. The shots are handheld, so not entirely stationary, but I wouldn't have time to do that whole 3D process anyway. But you did give me a good idea for how to match the comps in different shots. I'll post it here if it works. And also, yeah, I've used the image plane 3D instead of the normal transform before, and that is a good way to at least maintain the aspect ratio. I'll probably end up using that technique again. Thanks.